PB2340: FIRST LINE THERAPY FOR DIFFUSE LARGE B CELL LYMPHOMA AMONGPATIENTS AGED LESS THAN 60 YEARS: A TUNISIAN MULTICENTER EXPERIENCE.
Authors: Kmira Zahra, Imtinène Belaid, Karima Kacem, Moez Elloumi, Amel Mezlini, Fehmi Msaddek, Ben Othman Tarek, Toumi Nabil, Raihane Ben Lakhal, Abderrahim Khelif, Ben Ahmed Slim, Khanfir Afef, Adnene Laatiri
Journal: HemaSphere (2023)

Topic: 19. Aggressive Non-Hodgkin lymphoma - Clinical Background: The standard treatment of diffuse large B-cell lymphoma (DLBCL) remains chemo-immunotherapy with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone). Though this modality is safe and effective, up to 45%–50% of patients will relapse. Aims: To report the epidemiologic, clinical featuresand therapeutic results of DLBCL in patients≤60 years. Methods: It is a multicenter retrospective study including 399 patients aged less than 60 years with newly diagnosed DLBCL, treated between January 2013 and December 2020. The diagnosis was confirmed according to the WHO Classification of Hematological malignancies. Disease stage was determined according to Ann Arbor staging system. Patients were treated according to the national protocol non-Hodgkin’s lymphoma 2013 (NHL 2013). Patients ≤ 60years with age adjusted international prognostic index (aa-IPI) at 0 were treated with 6courses of CHOP21+/-Rituximab ® (NHL 2013-1). Patients aged between 16-60 years with aa-IPI 1 were treated with 8 courses of CHOP21+/-Rituximab ® (NHL 2013-2A)and those with IPI 2 or 3 were treated with 4courses of CHOP14+/-Rituximab ® followed by autologous stem cell transplantation (ASCT) for responders (NHL 2013-2B). The response was evaluated with the International Working Group (IWG) Response Criteria for NHL. The overall survival (OS) and event-free survival (EFS) were estimated with Kaplan Meier. Results: The median age was 42,7 years (16-60) with a male predominance (sex ratio 1.31). At diagnosis, the double localization (nodal and extra nodal) was observed in 207 patients (52%). B symptoms were present in 35,8% of cases. An altered performance status (≥2) was noted in 17,6% of the cases. A raised LDH level was observed in 233 patients (58,4%). The advanced stage (III and IV) was observed in 54%. Bulky mass was noted in 23,6% of cases. Aa-IPI was at 0 in 96 patients (24%) (NHL2013-1), at 1 in 140 patients (35%) (NHL2013-2A) and at 2-3 in 163 patients (41%) (NHL2013-2B). Rituximab was not received in 37 patients (9,3%). The intercourse period was not respected in 25% of cases due to hematological toxicity. Seven patients died before the interim evaluation (1,7%) due to tumor progression in 2 cases and toxic death in 5 patients (1,25%). For the 392 patients, the interim evaluation showed a global response (CR+ R>75%), a partial response (50-75%), a failure and a progression in 70,5%, 20,5%, 5% and4% of cases, respectively. At the end of treatment, 364 patients were evaluable (toxic death in 2 cases and death from tumor progression in 26 cases), the global response, the partial Response, the failure and the progression were observed in 89,5%, 2,7%, 1,9% and 5,7% of cases, respectively. In total, the treatment related mortality in our study was 1,7%.The global response was 84,3% (81/96patients) in the group LNH 2013-1, 87,8% (123/140patients) in the group NHL2013-2A and 74,8% (122/163patients) in the group NHL2013-2B. From the 122 responders in the group NHL2013-2B, the ASCT was realized in 87 cases (71%).The relapse rate was 13, 5% (44 patients from 326 responders). The 5-year OS for patients treated according NHL 2013-1, NHL 2013-2A and NHL 2013-2B was 88,3%, 80% and 64% (p=0.001), respectively. The 5-year RFS for patients treated according NHL 2013-1, NHL 2013-2A and NHL 2013-2B was 92%, 75% and 80% (p=0.01), respectively. The 5-year EFS for patients treated according NHL 2013-1, NHL 2013-2A and NHL 2013-2B was 80%, 74% and 60% (p=0.01), respectively. Summary/Conclusion: Our results can be improved by the determination of the clonal proliferation (germinal center B-cell (GCB) or activated B-cell (ABC)), by the use of PET scan for a better therapeutic evaluation and by the respect of ACST for high risk patients. Keywords: Chemotherapy, B cell lymphoma, Autologous hematopoietic stem cell transplantation